Defiant: The Manny Pacquiao ObsessionAt age 40, what drives Manny Pacquiao to keep fighting, long past the age when most fighters hang up the gloves?SI Staff|Share on FacebookShare on XAdd us as a preferred sourceAt age 40, what drives Manny Pacquiao to keep fighting, long past the age when most fighters hang up the gloves?Loading recommendations... Please wait while we load personalized content recommendationsPublished Jan 17, 2019 | Modified Jan 17, 2019SI STAFFShare on FacebookShare on XHome/Boxing